Philip Stewart

Summary

Affiliation: Montana State University
Country: USA

Publications

  1. ncbi request reprint Mechanisms of antibiotic resistance in bacterial biofilms
    Philip S Stewart
    Center for Biofilm Engineering, Department of Chemical Engineering, Montana State University, Bozeman, Montana 59717 3980, USA
    Int J Med Microbiol 292:107-13. 2002
  2. pmc Robustness analysis of culturing perturbations on Escherichia coli colony biofilm beta-lactam and aminoglycoside antibiotic tolerance
    Trevor R Zuroff
    Department of Chemical and Biological Engineering, Center for Biofilm Engineering, Montana State University, Bozeman MT 59717, USA
    BMC Microbiol 10:185. 2010
  3. pmc Diffusion in biofilms
    Philip S Stewart
    Center for Biofilm Engineering, Montana State University Bozeman, 59717 3980, USA
    J Bacteriol 185:1485-91. 2003
  4. ncbi request reprint New ways to stop biofilm infections
    Philip S Stewart
    Center for Biofilm Engineering, Montana State University Bozeman, Bozeman, MT 59717, USA
    Lancet 361:97. 2003
  5. doi request reprint Physiological heterogeneity in biofilms
    Philip S Stewart
    Center for Biofilm Engineering, Montana State University, Bozeman, Montana 59717 3980, USA
    Nat Rev Microbiol 6:199-210. 2008
  6. ncbi request reprint Observations of cell cluster hollowing in Staphylococcus epidermidis biofilms
    P S Stewart
    Department of Chemical Engineering, Center for Biofilm Engineering, Montana State University Bozeman, Bozeman, MT, USA
    Lett Appl Microbiol 44:454-7. 2007
  7. ncbi request reprint Biofilm penetration and disinfection efficacy of alkaline hypochlorite and chlorosulfamates
    P S Stewart
    Center for Biofilm Engineering, Montana State University Bozeman, Bozeman, MT 59717 3980, USA
    J Appl Microbiol 91:525-32. 2001
  8. ncbi request reprint Antibiotic resistance of bacteria in biofilms
    P S Stewart
    Center for Biofilm Engineering and Department of Chemical Engineering, Montana State University, Bozeman, MT 59717 3980, USA
    Lancet 358:135-8. 2001
  9. pmc Effect of catalase on hydrogen peroxide penetration into Pseudomonas aeruginosa biofilms
    P S Stewart
    Center for Biofilm Engineering, Montana State University Bozeman, Bozeman, Montana 59717 3980, USA
    Appl Environ Microbiol 66:836-8. 2000
  10. ncbi request reprint A review of experimental measurements of effective diffusive permeabilities and effective diffusion coefficients in biofilms
    P S Stewart
    Center for Biofilm Engineering and Department of Chemical Engineering, Montana State University, Bozeman, Montana 59717, USA
    Biotechnol Bioeng 59:261-72. 1998

Research Grants

Collaborators

Detail Information

Publications51

  1. ncbi request reprint Mechanisms of antibiotic resistance in bacterial biofilms
    Philip S Stewart
    Center for Biofilm Engineering, Department of Chemical Engineering, Montana State University, Bozeman, Montana 59717 3980, USA
    Int J Med Microbiol 292:107-13. 2002
    ..Disabling biofilm resistance may enhance the ability of existing antibiotics to clear infections involving biofilms that are refractory to current treatments...
  2. pmc Robustness analysis of culturing perturbations on Escherichia coli colony biofilm beta-lactam and aminoglycoside antibiotic tolerance
    Trevor R Zuroff
    Department of Chemical and Biological Engineering, Center for Biofilm Engineering, Montana State University, Bozeman MT 59717, USA
    BMC Microbiol 10:185. 2010
    ..The predictability of an antibiotic tolerance response is essential to developing, testing, and employing antimicrobial strategies...
  3. pmc Diffusion in biofilms
    Philip S Stewart
    Center for Biofilm Engineering, Montana State University Bozeman, 59717 3980, USA
    J Bacteriol 185:1485-91. 2003
  4. ncbi request reprint New ways to stop biofilm infections
    Philip S Stewart
    Center for Biofilm Engineering, Montana State University Bozeman, Bozeman, MT 59717, USA
    Lancet 361:97. 2003
  5. doi request reprint Physiological heterogeneity in biofilms
    Philip S Stewart
    Center for Biofilm Engineering, Montana State University, Bozeman, Montana 59717 3980, USA
    Nat Rev Microbiol 6:199-210. 2008
    ....
  6. ncbi request reprint Observations of cell cluster hollowing in Staphylococcus epidermidis biofilms
    P S Stewart
    Department of Chemical Engineering, Center for Biofilm Engineering, Montana State University Bozeman, Bozeman, MT, USA
    Lett Appl Microbiol 44:454-7. 2007
  7. ncbi request reprint Biofilm penetration and disinfection efficacy of alkaline hypochlorite and chlorosulfamates
    P S Stewart
    Center for Biofilm Engineering, Montana State University Bozeman, Bozeman, MT 59717 3980, USA
    J Appl Microbiol 91:525-32. 2001
    ..The purpose of this study was to compare the efficacy, in terms of bacterial biofilm penetration and killing, of alkaline hypochlorite (pH 11) and chlorosulfamate (pH 5.5) formulations...
  8. ncbi request reprint Antibiotic resistance of bacteria in biofilms
    P S Stewart
    Center for Biofilm Engineering and Department of Chemical Engineering, Montana State University, Bozeman, MT 59717 3980, USA
    Lancet 358:135-8. 2001
    ..In biofilms, resistance seems to depend on multicellular strategies. We summarise the features of biofilm infections, review emerging mechanisms of resistance, and discuss potential therapies...
  9. pmc Effect of catalase on hydrogen peroxide penetration into Pseudomonas aeruginosa biofilms
    P S Stewart
    Center for Biofilm Engineering, Montana State University Bozeman, Bozeman, Montana 59717 3980, USA
    Appl Environ Microbiol 66:836-8. 2000
    ..Catalase protects aggregated bacteria by preventing full penetration of hydrogen peroxide into the biofilm...
  10. ncbi request reprint A review of experimental measurements of effective diffusive permeabilities and effective diffusion coefficients in biofilms
    P S Stewart
    Center for Biofilm Engineering and Department of Chemical Engineering, Montana State University, Bozeman, Montana 59717, USA
    Biotechnol Bioeng 59:261-72. 1998
    ....
  11. pmc Electrolytic generation of oxygen partially explains electrical enhancement of tobramycin efficacy against Pseudomonas aeruginosa biofilm
    P S Stewart
    Center for Biofilm Engineering, Montana State University Bozeman 59717 3980, USA
    Antimicrob Agents Chemother 43:292-6. 1999
    ..8-log enhancement of killing resulted. The enhancement of antibiotic killing by oxygen was not due simply to physical disturbances caused by sparging the gas because similar delivery of gaseous hydrogen caused no enhancement whatsoever...
  12. ncbi request reprint Analysis of biocide transport limitation in an artificial biofilm system
    P S Stewart
    Center for Biofilm Engineering, Montana State University, Bozeman 59717, USA
    J Appl Microbiol 85:495-500. 1998
    ..This result demonstrates that transport limitation can impact antimicrobial performance against biofilms not only of oxidizing biocides but also of nonoxidizing agents...
  13. pmc Biopolymer and water dynamics in microbial biofilm extracellular polymeric substance
    Jennifer A Hornemann
    Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT, USA
    Biomacromolecules 9:2322-8. 2008
    ..The dependence of diffusion on antimicrobial and environmental challenges suggests the polymer molecular dynamics measured by NMR are a sensitive indicator of biofilm function...
  14. pmc Hypothesis for the role of nutrient starvation in biofilm detachment
    Stephen M Hunt
    Center for Biofilm Engineering, Montana State University, Bozeman, MT 59717 3980, USA
    Appl Environ Microbiol 70:7418-25. 2004
    ..The model was also able to predict biofilm sloughing resulting solely from this detachment mechanism. These results support the conjecture that nutrient starvation is an environmental cue for the release of microbes from a biofilm...
  15. pmc Localized gene expression in Pseudomonas aeruginosa biofilms
    Ailyn P Lenz
    Department of Microbiology, Montana State University, Bozeman, MT 59717, USA
    Appl Environ Microbiol 74:4463-71. 2008
    ..The LCMM/qRT-PCR technique can be used to resolve and quantify this RNA variability at high spatial resolution...
  16. doi request reprint Anti-biofilm properties of chitosan-coated surfaces
    Ross P Carlson
    Center for Biofilm Engineering and Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT 59717, USA
    J Biomater Sci Polym Ed 19:1035-46. 2008
    ..This suggests chitosan disrupts cell membranes as microbes settle on the surface. Chitosan offers a flexible, biocompatible platform for designing coatings to protect surfaces from infection...
  17. ncbi request reprint Biofilms in chronic wounds
    Garth A James
    Center for Biofilm Engineering, Montana State University Bozeman, Bozeman, Montana 59717, USA
    Wound Repair Regen 16:37-44. 2008
    ..Bacterial biofilm prevalence in specimens from chronic wounds relative to acute wounds observed in this study provides evidence that biofilms may be abundant in chronic wounds...
  18. pmc Rapid diffusion of fluorescent tracers into Staphylococcus epidermidis biofilms visualized by time lapse microscopy
    Suriani Abdul Rani
    Center for Biofilm Engineering and Department of Chemical Engineering, Montana State University Bozeman, Bozeman, MT 59717 3980, USA
    Antimicrob Agents Chemother 49:728-32. 2005
    ..6 x 10(-6) cm(2) s(-1), or 32% of the value in water. This study provides direct, visual confirmation that solutes the size of many antibiotics and biocides can diffuse rapidly into biofilms...
  19. pmc Direct visualization of spatial and temporal patterns of antimicrobial action within model oral biofilms
    Shoji Takenaka
    Center for Biofilm Engineering, Montana State University Bozeman, Bozeman, MT 59717 3980, USA
    Appl Environ Microbiol 74:1869-75. 2008
    ..The CAM staining technique has the potential to provide information about the rate of antimicrobial penetration, the presence of tolerant subpopulations, and the extent of biomass removal effected by a treatment...
  20. pmc Daptomycin rapidly penetrates a Staphylococcus epidermidis biofilm
    Philip S Stewart
    Center for Biofilm Engineering, Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT 59717 3980, USA
    Antimicrob Agents Chemother 53:3505-7. 2009
    ..The diffusion coefficient of daptomycin in the biofilm was 28% of its value in pure water. Daptomycin activity against staphylococci embedded in biofilms is unlikely to be limited by penetration of the antibiotic into the biofilm...
  21. doi request reprint Chemical and antimicrobial treatments change the viscoelastic properties of bacterial biofilms
    Warren L Jones
    Department of Civil Engineering, Montana State University, Bozeman, Montana, USA
    Biofouling 27:207-15. 2011
    ..Understanding biofilm rheology and how it is affected by chemical treatment could lead to improvements in biofilm control...
  22. ncbi request reprint Magnetic resonance microscopy of biofilm structure and impact on transport in a capillary bioreactor
    Joseph D Seymour
    Department of Chemical and Biological Engineering and Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
    J Magn Reson 167:322-7. 2004
    ..The data demonstrate the ability of magnetic resonance microscopy to study spatially resolved processes in bacterial biofilms, thus providing a basis for future studies of spatially resolved metabolism and in vivo clinical detection...
  23. pmc Spatial patterns of DNA replication, protein synthesis, and oxygen concentration within bacterial biofilms reveal diverse physiological states
    Suriani Abdul Rani
    Center for Biofilm Engineering, Montana State University Bozeman, Bozeman, MT 59717 3980, USA
    J Bacteriol 189:4223-33. 2007
    ..The variety of activity states represented in a biofilm may contribute to the special ecology and tolerance to antimicrobial agents of biofilms...
  24. doi request reprint A method for growing a biofilm under low shear at the air-liquid interface using the drip flow biofilm reactor
    Darla M Goeres
    Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
    Nat Protoc 4:783-8. 2009
    ..The entire procedure takes 13 h of active time that is distributed over 5 d...
  25. pmc Loss of viability and induction of apoptosis in human keratinocytes exposed to Staphylococcus aureus biofilms in vitro
    Kelly R Kirker
    Center for Biofilm Engineering, Montana State University, Bozeman, MT 59717, USA
    Wound Repair Regen 17:690-9. 2009
    ..aureus planktonic cells and biofilms inhibit scratch closure. Furthermore, S. aureus biofilms significantly reduced HK viability and significantly increased HK apoptosis compared with planktonic S. aureus...
  26. pmc Stratified growth in Pseudomonas aeruginosa biofilms
    Erin Werner
    Center for Biofilm Engineering, Montana State University Bozeman, Bozeman, MT 59717 3980, USA
    Appl Environ Microbiol 70:6188-96. 2004
    ..These results show that while mature P. aeruginosa biofilms contain active, growing cells, they can also harbor large numbers of cells that are inactive and not growing...
  27. pmc Transmission electron microscopic study of antibiotic action on Klebsiella pneumoniae biofilm
    Jeff Zahller
    Center for Biofilm Engineering and Department of Chemical Engineering, Montana State University Bozeman, 366 EPS Building, Bozeman, MT 59717 3980, USA
    Antimicrob Agents Chemother 46:2679-83. 2002
    ..Because the bacteria nevertheless survived antibiotic treatment, some protective mechanism other than inadequate penetration must have been at work in the biofilm...
  28. ncbi request reprint Escherichia coli O157:H7 requires colonizing partner to adhere and persist in a capillary flow cell
    Benjamin J Klayman
    Center for Biofilm Engineering, Montana State University, 366 EPS Building, Bozeman, Montana 59717, USA
    Environ Sci Technol 43:2105-11. 2009
    ..In many cases, bacteria have been shown to gain a fitness advantage when residing in a mixed-species versus single-..
  29. pmc Spatial and temporal patterns of biocide action against Staphylococcus epidermidis biofilms
    William M Davison
    Center for Biofilm Engineering and Department of Chemical and Biological Engineering, Montana State University Bozeman, Bozeman, MT 59717 3980, USA
    Antimicrob Agents Chemother 54:2920-7. 2010
    ..These results underscore the distinction between biofilm removal and killing and reinforce the critical role of biocide reactivity in determining the rate of biofilm penetration...
  30. doi request reprint Measurements of accumulation and displacement at the single cell cluster level in Pseudomonas aeruginosa biofilms
    Benjamin J Klayman
    Center for Biofilm Engineering, 366 EPS Building, Montana State University, Bozeman, MT 59717, USA
    Environ Microbiol 10:2344-54. 2008
    ..This work provides a more detailed quantitative experimental observation of biofilm behaviour than has been described previously...
  31. ncbi request reprint Magnetic resonance microscopy analysis of advective transport in a biofilm reactor
    Erica L Gjersing
    Department of Chemical and Biological Engineering and Center for Biofilm Engineering, Montana State University, 306 Cobleigh Hall, PO Box 173920, Bozeman, Montana 59717 3920, USA
    Biotechnol Bioeng 89:822-34. 2005
    ....
  32. ncbi request reprint Modelling protection from antimicrobial agents in biofilms through the formation of persister cells
    Mark E Roberts
    Center for Biofilm Engineering and Department of Chemical and Biological Engineering, Montana State University Bozeman, Bozeman, MT 59717 3980, USA
    Microbiology 151:75-80. 2005
    ..This modelling study provides motivation for further investigation of the hypothetical persister cell state as an explanation for biofilm resistance to antimicrobial agents...
  33. pmc Modeling antibiotic tolerance in biofilms by accounting for nutrient limitation
    Mark E Roberts
    Center for Biofilm Engineering and Department of Chemical and Biological Engineering, Montana State University Bozeman, Bozeman, Montana 59717 3980, USA
    Antimicrob Agents Chemother 48:48-52. 2004
    ..The results support the important contributions of nutrient limitation and slow growth to the antibiotic tolerance of microorganisms in biofilms...
  34. pmc Oxygen limitation contributes to antibiotic tolerance of Pseudomonas aeruginosa in biofilms
    Giorgia Borriello
    Center for Biofilm Engineering and Department of Chemical Engineering, Montana State University Bozeman, Bozeman, MT 59717 3980, USA
    Antimicrob Agents Chemother 48:2659-64. 2004
    ..Local oxygen limitation and the presence of nitrate may contribute to the reduced susceptibilities of P. aeruginosa biofilms causing infections in vivo...
  35. pmc Penetration of rifampin through Staphylococcus epidermidis biofilms
    Zhilan Zheng
    Center for Biofilm Engineering and Department of Chemical Engineering, Montana State University Bozeman, Bozeman, Montana 59717 3980, USA
    Antimicrob Agents Chemother 46:900-3. 2002
    ..Penetration was demonstrated by a simple diffusion cell bioassay and by transmission electron microscopic observation of antibiotic-affected cells at the distal edge of the biofilm...
  36. ncbi request reprint Biofilm-control strategies based on enzymic disruption of the extracellular polymeric substance matrix--a modelling study
    Joao B Xavier
    Center for Biofilm Engineering and Department of Chemical and Biological Engineering, Montana State University Bozeman, Bozeman, MT 59717 3980, USA
    Microbiology 151:3817-32. 2005
    ..This study demonstrates the feasibility and limits of implementing biofilm-control strategies based on attacking the EPS...
  37. pmc Arginine or nitrate enhances antibiotic susceptibility of Pseudomonas aeruginosa in biofilms
    Giorgia Borriello
    Center for Biofilm Engineering and Department of Clinical Engineering, Montana State University Bozeman, 409 Cobleigh Hall, Bozeman, Montana 59717 3980, USA
    Antimicrob Agents Chemother 50:382-4. 2006
    ..Arginine or nitrate also enhanced the killing by these antibiotics in mature biofilms, reducing viable cell counts by a factor of 10 to 100 beyond that achieved by antibiotics alone...
  38. pmc Removal and inactivation of Staphylococcus epidermidis biofilms by electrolysis
    Christine Rabinovitch
    Center for Biofilm Engineering and Department of Chemical and Biological Engineering, Montana State University Bozeman, Bozeman, MT 59717 3980, USA
    Appl Environ Microbiol 72:6364-6. 2006
    ..These treatments resulted in killing (2.1-log reduction) and removal (4.0-log reduction) of viable cells at the anode and cathode, respectively, within a few minutes...
  39. ncbi request reprint A microtiter-plate screening method for biofilm disinfection and removal
    Betsey Pitts
    Center for Biofilm Engineering, Montana State University, Bozeman, MT 59717, USA
    J Microbiol Methods 54:269-76. 2003
    ..Using these assays, agents can be ranked by their ability to remove or kill biofilm...
  40. pmc A three-dimensional computer model of four hypothetical mechanisms protecting biofilms from antimicrobials
    Jason D Chambless
    Center for Biofilm Engineering and Department of Chemical and Biological Engineering, Montana State University Bozeman, Bozeman, MT 59717 3980, USA
    Appl Environ Microbiol 72:2005-13. 2006
    ..Each of the mechanisms could be a plausible avenue of biofilm protection...
  41. pmc Role of nutrient limitation and stationary-phase existence in Klebsiella pneumoniae biofilm resistance to ampicillin and ciprofloxacin
    Jeff N Anderl
    Center for Biofilm Engineering, Montana State University, Bozeman, Montana 59717 3980, USA
    Antimicrob Agents Chemother 47:1251-6. 2003
    ..In these inactive regions, bacteria are less susceptible to killing by antibiotics...
  42. ncbi request reprint High-density targeting of a viral multifunctional nanoplatform to a pathogenic, biofilm-forming bacterium
    Peter A Suci
    Department of Microbiology, Center for BioInspired Nanomaterials, Montana State University, Bozeman, MT 59717, USA
    Chem Biol 14:387-98. 2007
    ..aureus biofilm. These results demonstrate that multifunctional nanoplatforms based on protein cage architectures have significant potential as tools for both diagnosis and targeted treatment of recalcitrant bacterial infections...
  43. pmc Secondary flow mixing due to biofilm growth in capillaries of varying dimensions
    Jennifer A Hornemann
    Department of Chemical and Biological Engineering, Montana State University, Bozeman, Montana, USA
    Biotechnol Bioeng 103:353-60. 2009
    ..Since this is the "standard 1 mm" size capillary used in confocal microscopy laboratory bioreactors to investigate biofilm properties, it is important to understand how these enhanced flows impact bioreactor transport...
  44. ncbi request reprint A three-dimensional computer model analysis of three hypothetical biofilm detachment mechanisms
    Jason D Chambless
    Center for Biofilm Engineering, and Department of Chemical and Biological Engineering, Montana State University Bozeman, Bozeman, Montana 59717 3980, USA
    Biotechnol Bioeng 97:1573-84. 2007
    ..The dynamics of biofilm decay during starvation were distinct for each detachment mechanism. These results show that detachment is a critical determinant of biofilm structure and of the dynamics of biofilm accumulation and loss...
  45. pmc Contributions of antibiotic penetration, oxygen limitation, and low metabolic activity to tolerance of Pseudomonas aeruginosa biofilms to ciprofloxacin and tobramycin
    Marshall C Walters
    Center for Biofilm Engineering, Department of Chemical Engineering, Montana State University Bozeman, Bozeman, Montana 59717 3980, USA
    Antimicrob Agents Chemother 47:317-23. 2003
    ..These results show that oxygen limitation and low metabolic activity in the interior of the biofilm, not poor antibiotic penetration, are correlated with antibiotic tolerance of this P. aeruginosa biofilm system...
  46. ncbi request reprint A genetic basis for Pseudomonas aeruginosa biofilm antibiotic resistance
    Thien Fah Mah
    Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, New Hampshire 03755, USA
    Nature 426:306-10. 2003
    ..Our results indicate that biofilms themselves are not simply a diffusion barrier to these antibiotics, but rather that bacteria within these microbial communities employ distinct mechanisms to resist the action of antimicrobial agents...
  47. ncbi request reprint Biofilms strike back
    GEORGE A O'TOOLE
    Nat Biotechnol 23:1378-9. 2005
  48. pmc Comparison of the antimicrobial effects of chlorine, silver ion, and tobramycin on biofilm
    Jaeeun Kim
    School of Chemical and Biological Engineering, Seoul National University, Sillim dong, Gwanak Gu, Seoul, South Korea
    Antimicrob Agents Chemother 52:1446-53. 2008
    ..This observation makes sense when the different oxidative reactivities of chlorine, silver, and tobramycin are considered...
  49. ncbi request reprint Diffusion coefficient of fluoride in dental plaque
    Philip S Stewart
    J Dent Res 84:1087; author reply 1087-8. 2005
  50. ncbi request reprint Pretreatment for membrane water treatment systems: a laboratory study
    Christopher F Wend
    Pacific Northwest National Laboratories, PO Box 999, MSIN K7 94, Richland, WA 99352, USA
    Water Res 37:3367-78. 2003
    ..These results suggest that biological treatment may be valuable in reducing membrane fouling while reducing the amount of disinfectants used in pretreatment...
  51. pmc The effect of the chemical, biological, and physical environment on quorum sensing in structured microbial communities
    Alexander R Horswill
    Department of Microbiology, University of Iowa, Iowa, IA 52242, USA
    Anal Bioanal Chem 387:371-80. 2007
    ..As these studies continue to refine our understanding of these mechanisms, an emerging challenge is to identify if and when the local environment can affect signaling...

Research Grants7

  1. Antibiotic Susceptibility of Bacteria in Biofilms
    Philip Stewart; Fiscal Year: 2005
    ..This project will afford a rich interdisciplinary training experience for the three participating graduate students. ..
  2. Healing Chronic Wounds by Controlling Microbial Biofilm
    Philip Stewart; Fiscal Year: 2007
    ..Furthermore, the results of this research may impact the treatment of other biofilm-related diseases, such as osteomyelitis, endocarditis, prostatitis, otitis media, and sinusitis. ..
  3. Healing Chronic Wounds by Controlling Microbial Biofilm
    Philip Stewart; Fiscal Year: 2007
    ..Futhermore, the results of this research may impact the treatment of other biofilm-related diseases, such as osteomyelitis, endocarditis, prostatitis, otitis media, and sinusitis. ..